Conventionally, a user requires that an image forming device such as a copying machine and a printer reduce the number of output sheets. In a case of reducing the number of output sheets in performing a printing operation, it is general to select one from two output modes: (i) a double-side printing output mode for printing both front and back sides and (b) a 2-in-1 or 4-in-1 output mode for downsizing image data so that the image data, corresponding to plural pages of original images, is printed on each output sheet.
In the image forming device, upon outputting image data by using these processing functions, the user inputs setting of operation via an operation panel, so as to set a printing condition desired by the user.
For example, (1) Japanese Unexamined Patent Publication No. 84952/1993 (Tokukaihei 11-84952)(Publication date: Mar. 30, 1999) discloses a copy mode display device by which the user can select a recommended copy mode (recommended output mode) which can reduce the number of output sheets. Specifically, in the technique (1), a total number of copy sheets required in printing documents (required print output sheets number) is calculated, and when the required print output sheets number exceeds a predetermined threshold value, the recommended output mode such as a 2-in-1 single-side output mode and a 2-in-1 double-side output mode is displayed in a display section.
In the technique (1), the required print output sheets number is calculated on the basis of (i) an approximately calculated number of documents which is calculated by detecting means for detecting a height of documents stacked on a document table and (ii) a desired print copies number desired by the user in performing the printing operation. The desired print copies number is a number of output copies.
Incidentally, there is a case where a copying machine includes post-processing means for performing various kinds of post-processes with respect to printed output sheets. For example, an arrangement including a post-processing device such as a stapling device provided in a preceding stage of a delivered sheet tray (delivery tray) is known.
In the stapling process, several numbers of output sheets are stapled, so that some kinds of arrangements and stapling pins of the stapling device cannot staple the output sheets whose amount exceeds a predetermined number. Then, for example, (2) Japanese Unexamined Patent Publication No. 222641/1994 (Tokukaihei 6-222641)(Publication date: Aug. 12, 1994) discloses a copying system device (copying machine) for adjusting the number of output sheets so that it is possible to staple the output sheets even when the number of documents exceeds a standard number of the stapling process. In this technique (2), the number of documents set in the copying machine is counted in advance, and when the obtained number of documents exceeds the standard number of the stapling process, an output mode is automatically switched from (i) a single-side printing mode without downsizing to (ii) a double-side printing mode.
Here, as to a conventional image forming device having a general arrangement, in a case of printing the image data corresponding to plural pages so as not to exceed a predetermined number of output sheets whose amount is less than the plural pages, it is necessary to set “which function is to be used” after calculating the number of pages of image data which should be printed on each output sheet so as to set an appropriate printing condition, so that this brings about such a problem that the user is required to perform troublesome operations.
Further, in a case of printing the image data of documents whose amount is so large onto the output sheets, the user has to begin by counting the number of documents, so that the user has to perform more troublesome operations.
On the other hand, the foregoing techniques (1) and (2) can solve the aforementioned problems to some extent. However, these techniques bring about the following problems, so that effects thereof are still insufficient.
For example, in the technique (1), in printing the image data of documents whose amount is so large at all once, the number of output sheets may be limited depending on a condition of the copying machine, so that the user has to confirm the limit each time, thereby bringing about such a problem that operations are troublesome.
That is, when an amount of documents is so large that the number of documents cannot be concretely grasped, a printing condition set in the copying machine is prioritized. At this time, the user does not have to count the number of documents. However, for example, when an amount of output sheets remaining in a feeding tray of the copying machine and an amount of remaining output sheets that can be delivered to a delivery tray are the limit of the number of output sheets, the user has to confirm the limit.
While, in the technique (2), the output mode includes only two modes: a single-side printing mode and a double-side printing mode. Thus, when the number of documents is more than twice of the standard number of the stapling process, this brings about such a problem that it is substantially impossible to use the stapling process.
For example, when the standard number of the stapling process is 30 and the number of documents is 80, the number of documents exceeds 60 which is twice of the standard number. Thus, even when both sides of every sheet is printed, the number of output sheets is not within 30 sheets of the standard number. As a result, the printing operation is stopped.
Further, when the number of documents is within twice of the standard number of the stapling process, only the double-side printing can be performed, so that this arrangement does not satisfies the requirement of the user. Thus, the user has to confirm whether it is possible to perform the stapling process or not each time, so that this brings about such a problem that operations are troublesome.
Further, the foregoing problems are brought about not only in the copying machine but also in a printer which performs printing operation in response to data received from a computer. That is, also in a case where the printing operation is performed in response to a large quantity of data received from a computer, the printing condition of the printer is prioritized, so that the user has to confirm the limit of the number of output sheets as in the aforementioned case.